Secretary of State Cyrus R. Vance and Soviet Ambassador Anatoliy F. Dobryinin discussed the Afghanistan crisis yesterday amid growing speculation that the United States and the Soviet Union are moving toward talks about neutralization of the Soviet-occupied nation.

State Department spokesman Hodding Carter later denied a published report that Vance plans to meet Soviet Foreign Minister Andrei Gromyko for further discussions next month.

But, department sources, pointing to the critical illness of Yugoslavia's President Tito, said that if Tito dies, both Vance and Gromyko are expected to attend the funeral and almost certainly would use the occasion to discuss Afghanistan.

Despite these and other signs of possible movement on the Afghanistan situation, Hodding Carter sought to tamp down speculation that the two superpowers are close to resolving the tensions that overtook the U.S.-Soviet relations in the wake of Moscow's Dec. 27 invasion of Afghanistan.

The spokesman reiterated that the United States insists on the withdrawal of all Soviet troops as an "antecedent" to any negotiations about Afghanistan's future status.

He also emphasized that, while Washington would welcome efforts by other countries to explore whether the Soviets are willing to pull their forces out, the United States does not intend to take the lead in these moves.

In private, department sources said the United States is skeptical about signals coming out of Moscow that the Soviets might be willing to negotiate a solution of the Afghan crisis. This skepticism, the sources added, is based on a U.S. belief that Moscow is interested not in a genuine pullout and neutralization of Afghanistan but in a cosmetic arrangement that would put an international seal of approval onSoviet control of that Southwest Asia country.

Still, the sources said, the Carter administration wants to keep its lines of communication with the Soviets open and is prepared to be flexible in its approach to the Afghan situation depending on how events move.

The administration's West European allies, working through the framework of the nine-member European Economic Commission, already have proposed talks about neutralizing Afghanistan under international guarantees, and Italian Prime Minister Francesco Cossiga is attempting to make preliminary soundings with the Soviets about carrying the matter further. m

During his round of consultations in Europe last week, Vance gave a U.S. green light for the allies to pursue their initiative. Subsequently, Soviet President Leonid I. Brezhnev, in a public speech in talks with U.S. businessman Armand Hammer, hinted at his willingness to explore a negotiated settlement.

It was because of this background that special attention was focused yesterday on the previously unannounced meeting between Vance and Dobrynin and a published assertion by New York Times columnist James Reston that a Vance-Gromyko meeting of Afghanistan is being planned.

But while State Department officials admitted Afghanistan was among the subjects discussed by Vance and Dobrynin, Hodding Carter denied the Reston report. He said: "There is no plan for such a meeting. Whether or not such a possibility would arise would depend on future events."

Department sources later noted the possibility that a Tito funeral would bring the two together in Belgrade. But they stressed that the United States remains much more skeptical than its European allies about the chances of any Soviet moves that would pave the way for meaningful negotiations in the near future.